The largest empire in modern history, the Mongol empire, progressed through much of the 13th century, covering vast territories across Eastern Europe and Asia; the bulk of the known world at that time. Emerging across a series of conquests and invasions, the Horde began its ventures into Southeast Asia beginning the mid 13th century; reaching Vietnam by 1257. Vietnam at that time lied along Kublai Khan’s path of interest towards Champa, facing the repeated pressures of invasion. Trần Hưng Đạo of the Trần Dynasty would proceed to resist the Horde with exceptional valour and ingenuity. Beyond Trần borders, the Champa Kings would eventually submit to Mongol suzerainty, after repeated attacks.
The Khmers, on the other hand, followed more or less the Champa policy, resolving to send tributes amid joint Viet-Siamese political ambitions and Mongol expansionism. The Siamese Sukhothai meanwhile, ever more weary of such advanced adversary, chose to accept Mongol supremacy. It was during these times that King Ramkhamhaeng (1279–1298) visited the Yuan court to show their loyalty several times.
Unlike the invasions of Eastern Europe and the Middle East, the court of Kublai Khan followed a policy of sending envoys to the Indochinese and Nusantara governments instead. Those subjects, in return submission, paid tribute to the Mongol court, including elephants, rhinoceroses, jewelry. One notable exception was during the Mongol invasion of Java, which followed the Majapahit King Kertanegara‘s (1268–1292) refusal to paid tribute. The battle result was a unique case of Javanese victory. Otherwise the peoples of Malaya, Sumatra, the Philippines and surrounding states were more or less ceremoniously accepted suzerainty.